<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>CSS盒子的定位</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        p {
            width:160px;
            border-width:thin;
            border-style:solid;
        }

        em {
            padding:6px;
            margin: 1em;
            border-width: thin;
            border-style: dashed;
            line-height: 6em;
            background-color: #ffcc00;
        }

        #box1 {
            width: 200px;
            height: 200px;
            background-color:bisque;
            border-width: thin;
            border-style: solid;
        }

        #boxabsolute {
            position: absolute;
            top:100px;
            left:240px;
            width: 100px;
            height: 100px;
            background-color:aliceblue;
            border-width: thin;
            border-style: dashed;
        }    </style>
</head>
<body>
    <p>正确的<em>认知</em>是<strong>非常</strong>重要的.</p>
    <div id="box1">
        内部<br>ss
        <div id="boxabsolute">
            绝对位置的盒子
        </div>
    </div>

</body>
</html>